The GPU subsystem drives the dual-display capabilities. The schematic outlines the routing to two independent micro-HDMI ports, supporting up to 4K resolution at 60Hz or dual 4K displays at 30Hz.
The schematic illustrates the LPDDR4 SDRAM integration.
[ BCM2711 SoC ] │ ├──► PCIe Gen 2 x1 ───► VIA VL805 USB 3.0 Controller ───► 2x USB 3.0 Ports │ ├──► RGMII Interface ──► Broadcom BCM54213PE PHY ────────► Gigabit Ethernet Port │ └──► Dual HDMI Blocks ──► 2x Micro-HDMI Outputs (4K Support) USB 3.0 Subsystem Raspberry Pi 4 Model B Full Schematic
The represents a significant architectural shift from its predecessors, moving toward a design that offers desktop-level performance through a complex system of power management, high-speed interfaces, and a modernized System on a Chip (SoC). While the official documentation provides "reduced schematics" rather than full manufacturing files, these diagrams reveal the intricate electrical relationships that power this high-performance single-board computer. 1. The Core Architecture: BCM2711 SoC and RAM
The release of the full schematic for the Raspberry Pi 4 Model B was a significant event for the open-source hardware community. While the Raspberry Pi Foundation primarily releases the schematics as a resource for accessory designers, system integrators, and advanced hobbyists, the document offers a fascinating glimpse into the engineering required to create a credit-card-sized, high-performance ARM computer. The GPU subsystem drives the dual-display capabilities
: This is the most frequently referenced section. Pay attention to the alternate function listings, as many pins serve multiple purposes.
: Power enters via a USB Type-C connector. The initial schematic revisions featured a design with a single pull-down resistor shared by both CC pins, causing compatibility issues with smart e-marked cables. Subsequent board revisions updated this to independent 5.1kΩ pull-down resistors on CC1 and CC2. [ BCM2711 SoC ] │ ├──► PCIe Gen
When working with the Pi 4 hardware, engineers frequently look to the schematic to resolve specific field failures:
If your Pi 4 has a solid red power LED but the green ACT (Activity) LED does not blink, check the voltage test points behind the PMIC chip. Locate the and 1V8 rails on the schematic.
Below is a summary of the major differences.
Instead, it focuses on the . This makes it most useful for understanding how to connect peripherals, design HATs (Hardware Attached on Top), and perform general hardware integration.